1. Field of the Invention
The present invention relates to a system and method for the monitoring and management of data. More particularly, but not by way of limitation, the present invention relates to a system for remotely monitoring conditions at a storage tank, containment, dispenser sump, pipeline, or the like, in an intrinsically safe manner and for the management of data collected as a result of such monitoring.
2. Background of the Invention
Conditions such as the level of fluid in a storage tank, vapor/fluid flow through a pipeline, or electrical usage are often of concern. The need to remotely monitor such conditions has long been recognized. While electronically readable instrumentation may be readily available for such monitoring, there are few options presently available for remote monitoring of such instrumentation.
For example, many homes use LP gas as a primary source of energy, particularly for heat producing appliances such as heating systems, ovens and ranges, water heaters, etc. Typically, each residence is provided with its own storage tank to supply the energy needs of that house. Periodically, the home owner must check the gauge of the tank and order more LP gas when the tank is low. Alternatively, a supplier may enter into an agreement with a home owner to periodically check the tank level and refill the tank when warranted. Either way, the periodic checking of the gauge is at a minimum inconvenient, unreliable and possibly costly.
One known alternative has been to equip such tanks with an electronically readable gauge. In one such configuration, the gauge is connected to a battery operated, radio frequency transmitter, which periodically transmits the tank level to a receiver located at the house. The receiver collects usage information and at some interval, calls the gas supplier via a phone line to report the collected information. The receiver may also be configured to recognize abnormal conditions and spontaneously report events such as a minimum level, usage indicative of a leak, etc. While a vast improvement over manual monitoring, these systems still suffer from a number of limitations.
By way of example, limitations include: there is no means for communicating back to the tank for purposes of control, special monitoring, or programming changes; transmissions occur at a fixed rate regardless of the need to update or changing conditions, thereby wasting transmitter battery life; transmissions occur asynchronously and thus, in an area with multiple transmitters, some transmissions will occasionally overlap, corrupting the data from both transmitters; etc.
While these limitations could be overcome in a system having bi-directional operation, providing a receiver at the monitoring location would further reduce battery life. Expected battery life with present systems is measured in years. Providing continuous power to a radio receiver in the battery powered unit at the tank would simply not be practical. Maintenance of the monitoring system for battery changes or recharging would approach the manpower requirements of simply manually reading the gauge.
If electrical service and a phone line were provided at the tank, there would obviously be no concerns of battery usage, however this situation would substantially increase the cost and complexity of a tank installation. In addition, having electrical devices in close proximity to the tank would increase the risk of fire from leaks or from the venting of gas which occurs at the end of the filling process when the fittings are disconnected.
It should be noted that other remote storage or delivery systems suffer from similar problems. Remote pipeline flow meters, electric meters, and the like require monitoring. Even when electronically readable gauges are utilized, monitoring systems typically either require special reading equipment to be transported to the gauge, require a permanent wired connection to a monitoring system or, if monitored wirelessly, report only at relatively fixed intervals.
Existing underground gasoline storage tanks provide an example off the problems associated with monitoring. Traditionally, a long graduated stick has been inserted into the tank to determine the amount of gasoline remaining in the tank. Over the past few years, concerns have grown over the deterioration of aging underground tanks and the impact of leaks on the environment. Government regulation has led to stringent monitoring requirements which are virtually impossible to perform manually.
Automated systems for monitoring underground tanks are not easily implemented in existing installations. To install the wiring for such a monitoring system, extensive excavation is required, often through the cement deck around the storage tanks. Equipment and wiring in or around the tanks must also be designed to prevent explosion or fire in the event of escaping fuel or vapor. Wireless monitoring has heretofore been impractical simply because it is difficult to transmit an RF signal from an underground location.
Market pressures continue to push for intrinsically safe electronic devices with improved response times and reliability for remote asset monitoring and control, such as monitoring and reporting storage tank leakage. As such, challenges remain and a need persists for improvements in systems and methods for remote asset monitoring and control, to which the present invention is directed.